I have only heard of rotary magnetic coupled devices called resolvers. The two versions that I have seen are an exciter input and sine and cosine outputs, or sine and cosine inputs and a resultant output. Another component used with encoders in robotics is the revolution counter - the motor may turn many rotations in an axis' range of motion.
The encoders provide an output that immediately indicates position information. A resolver produces signals that require demodulation. I'll talk about resolvers in another column, coming soon.
I don't know about you, but it seems to me that industry in general is really starting to confuse those two words. I've seen ads for "analog encoders" that talk about their internal technologies that perfectly describe a resolver. (I also dont' think the 90% of recent college graduates could define one difference).
Perhaps the analog encoders use a type of analog-signal detector (magnetic, capacitive...) and then perform the analog-to-digital conversions and information coding within the encoder case.
Jon, excellent article. I do considerable work in designing and developing work cells for robotic systems. Rotary and linear encoders are extremely valuable and accurate and provide just about the only reliable method for determining shaft position--which is critical to the function of the equipment. Having a basic understanding of how they work is paramount when trying to bring about a "fix" or troubleshooting a problem. Many thanks for the information.
Thanks, Bobj. My next column will introduce resolvers that produce an analog output. Interesting devices and a lot more to them that engineers might think.
Hi Jon, Nice summary of the various encoders and their applications to motors. I'll be sharing this material with my Controls Systems class at ITT Tech along with the encoder handbook. I look forward to reading your column on resolvers.
By experimenting with the photovoltaic reaction in solar cells, researchers at MIT have made a breakthrough in energy efficiency that significantly pushes the boundaries of current commercial cells on the market.
In a world that's going green, industrial operations have a problem: Their processes involve materials that are potentially toxic, flammable, corrosive, or reactive. If improperly managed, this can precipitate dangerous health and environmental consequences.
With LEDs dropping in price virtually every year, automakers have begun employing them, not only on luxury vehicles, but on entry-level models, as well.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
3 
